In this prevention trial, 32 communities in Africa (Tanzania, Zimbabwe, and South Africa) and 14 communities in Thailand will be randomized to either a community-based HIV voluntary counseling and testing (CBVCT) intervention or clinic-based standard VCT (SVCT) The CBVCT intervention has three major strategies (1) to make VCT more available in community settings, (2) to engage the community through outreach, and (3) to provide post-test support These three strategies are designed to change community norms and reduce risk for HIV infection among all community members, irrespective of whether they participated directly in the intervention Thus, we propose a community-level sampling approach as opposed to a cohort design to evaluate outcomes. The primary aim of this study is to test the hypothesis that communities receiving 2-1/2 years of CBVCT, relative to communities receiving 2-1/2 years of SVCT, will (Aim1) Have significantly lower prevalence of recent HIV infection In addition, we propose the following secondary aim to test the hypotheses that (Aim 2) CBVCT communities, relative to SVCT communities, will at the end of the intervention period report significantly less HIV risk, behavior, higher rates of HIV testing, more favorable social norms regarding HIV testing, more frequent discussions about HIV, more frequent disclosure of HIV status, less HIV-related :stigma, less frequent HIV-related negative life-events Finally, because of the importance of cost-effectiveness data to host and donor countries, we propose to (Aim 3) Assess the incremental cost-effectiveness of CBVCT compared to SVCT. To measure community-level change, a random sample of persons between the ages of 18 and 32 years of age from each community will be selected at baseline and post-intervention for measuring primary and secondary endpoints Aim 1 will be evaluated by comparing the post-intervention prevalence of recent infection measured by the sensitive/less sensitive HIV assay on all HIV-positive blood samples in the two arms of the study.